Question

An AC current is represented as 42.42sin628wt. RMS value of current and frequency are respectively - ​

Answer 1

An Alternating current is represented as 42.42sin(628t)

peak value of current , I = 42.42

use the formula, Rms value of current = peak value of current/√2

= I/√2

= 42.42/1.414 [ as we know, √2 = 1.414 ]

= 30A

hence, rms value of current is 30A.

now, angular frequency = 628

we know, angular frequency = 2π × frequency

or, 628 = 2πf ⇒ f = 628/2π

we know, π = 3.14

so, f = 628/2(3.14) = 628/6.28 = 100Hz

hence, frequency = 100Hz